JP2005269756A - Rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electric machine easily manufactured and stably obtaining a slide load. <P>SOLUTION: A vehicle AC power generator 100 is provided with a rotor 10 for integrally rotating together with a rotating shaft 14, a stator 4 disposed and facing the outer circumference of the rotor 10, frames 1, 2 for receiving the rotor 10 and the stator 4, stays 28, 29 protruding from outer circumferences of the frames, and a bushing 40 inserted into a stay hole 290 formed in the stay 29 and sliding along the central axis of the stay hole 290. A protrusion is formed on the inner circumference of the stay hole 290 facing the outer circumference of the bushing 40. A fastening margin is set between the bushing 40 and the stay hole 290. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rotating electrical machine such as a vehicle AC generator mounted on a passenger car, a truck, or the like.

Conventionally, as a structure for fixing a rotating electrical machine such as a vehicular generator mounted on a vehicle, a structure in which a bush attached to a cylindrical hole provided in a stay of a frame slides to absorb a dimension of an attachment portion is known. (For example, refer to Patent Document 1). As the bush shape, a cylindrical shape without splits or a cylindrical shape with splits is used. In the case of a split cylindrical bush, since it is easy to bend and deform, it is possible to stabilize the slide load when the rotating electric machine is attached.
JP-A-8-205464 (page 2-3, FIG. 3-11)

  By the way, in the bush disclosed in Patent Document 1, it is possible to realize a stable slide load by preventing deflection and deformation by adopting a split cylindrical shape as described above, Since the deformation is easy, there is an adverse effect that the accuracy of the hole position and the hole size deteriorates. In order to eliminate this harmful effect, it is sufficient to use a cylindrical bush with no split that does not cause deformation. However, using a bush with no split requires high-precision dimensional control and is not easy to manufacture, and the stay is If the outer diameter of the bush is too large relative to the inner diameter of the cylindrical hole provided in the cylinder, the slide load will be excessive and cannot be installed. There was a problem that a stable slide load could not be obtained due to warp.

  The present invention was created in view of the above points, and an object of the present invention is to provide a rotating electrical machine that can be easily manufactured and can obtain a stable slide load.

  In order to solve the above-described problems, a rotating electrical machine according to the present invention accommodates a rotor that rotates integrally with a rotating shaft, a stator that is disposed opposite to the outer periphery of the rotor, and the rotor and the stator. Frame, a stay protruding from the outer periphery of the frame, and a bush that is inserted into a mounting hole provided in the stay and slides along the central axis of the mounting hole. A convex portion is formed on the inner diameter side opposite to the outer peripheral surface of the rim, and a tightening margin is set between the bush and the mounting hole. The outer peripheral surface of the bush is partly in contact with the tip (top) of the convex part, not the entire inner peripheral surface of the mounting hole. If the tightening margin between the bush and the mounting hole is too tight, Since excessive stress that deforms and concentrates on the convex part is relieved, it is possible to prevent the slide load from becoming too large due to the dimensional accuracy of the bush and the mounting hole, and it is possible to obtain a stable slide load . In addition, even when the dimensional accuracy of the outer diameter of the non-split bush and the inner diameter of the mounting hole is relatively low, a stable sliding load can be obtained by providing an appropriate tightening allowance between the bush and the convex portion. Therefore, the bush and the mounting hole can be manufactured under low dimensional control, and the manufacturing becomes easy.

  Further, a pulley for transmitting a rotational driving force is attached to the rotating shaft described above, and it is desirable that the stay portion and the frame are attached to the engine via a bush, and the pulley is rotationally driven by the engine. By attaching the rotating electrical machine having the above-described structure around the bush to the engine, it is possible to prevent an excessive twisting load from being applied to the frame from the stay portion at the time of mounting, and to appropriately and reliably attach the rotating electrical machine to the engine. Can be done.

  The frame described above includes a front side frame having a stay portion having a mounting hole into which the bush is not inserted, and a rear side frame having a stay portion having a mounting hole into which the bush is inserted. It is desirable that the stay portion provided on the rear side and the stay portion provided on the rear side frame are screwed and fixed in a state in which the attachment portion on the engine side is sandwiched via the bush. As a result, even when the tightening force generated at the time of mounting by screw tightening is set to be large, the torsional load applied to the frame from the stay portion by sliding the bush can be made constant. Therefore, the tightening force generated by screw tightening can be set large, and the stay portion can be reliably attached to the engine attachment portion.

  Moreover, the internal thread surface of the bush mentioned above is formed with the internal thread groove, and it is desirable that the screw tightening and fixing to the mounting portion of the engine is performed using a bolt corresponding to the internal thread groove. In the present invention, a screw bush that is not split can be used, and the use of the screw bush eliminates the need for a nut combined with a bolt, thereby facilitating the work and reducing the number of parts.

  Moreover, it is desirable that a plurality of the convex portions described above are formed on the surface of the mounting hole facing the bush, and that the adjacent convex portions are smoothly connected. Thereby, when the bush is inserted into the mounting hole of the stay portion, excessive stress generated in a part of the concave portion between the adjacent convex portions can be relieved, and damage to the mounting hole can be prevented.

  Moreover, it is desirable that a plurality of the convex portions described above are formed on the surface of the mounting hole facing the bushing in a direction parallel to the central axis of the mounting hole. Alternatively, it is desirable that the convex portion described above is formed in a spiral shape that continuously circulates on the surface of the mounting hole facing the bush. Thereby, a bush can be supported by many convex parts, and the stress added to each convex part can be disperse | distributed.

  Moreover, it is desirable that the above-described convex portions are formed on the inner side of the both end surfaces of the mounting hole. As a result, the inner diameter in the vicinity of both end faces of the mounting hole can be made larger than the inner diameter of the portion where the convex portion is formed, and the portion with the larger inner diameter can be used as an insertion guide for the bush. Work at the time of insertion becomes easy.

  Hereinafter, an AC generator for a vehicle according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of an automotive alternator according to an embodiment. A vehicle alternator 100 shown in FIG. 1 includes a front frame 1, a rear frame 2, a stator 4, a rotor 10, a rectifier 24, a voltage controller 25, a brush device 26, a rear cover 27, and the like. Has been.

  Both the front side frame 1 and the rear side frame 2 have a bowl shape, and are fixed to each other by a plurality of bolts 3 in a state in which these openings are in direct contact with each other. A stator 4 is fixed to the inner periphery of the front side frame 1. A cylindrical bearing box 7 is formed integrally with the front side frame 1, and an iron bearing box 8 is attached to the rear side frame 2 with bolts 9 having knurling. The front side frame 1 is provided with stay portions 28 and 30 protruding toward the outer peripheral side, and the rear side frame 2 is provided with a stay portion 29 protruding toward the outer peripheral side. One stay portion 28 of the front frame 1 and the stay portion 29 of the rear frame 2 are formed at the same circumferential position, and the vehicle bracket 300 is sandwiched and tightened in a space formed between them. It functions as a mount stay for fixing the AC generator 100 for use. Further, the other stay portion 30 of the front frame 1 is formed at a circumferential position substantially opposite to the one stay portion 28, and the belt angle can be changed by varying the mounting angle of the vehicle alternator 100. It functions as an adjust stay that adjusts. A stay hole 290 as an attachment hole is formed in the stay portion 29 of the rear side frame 2, and a bush 40 that is a cylindrical member that is not split is press-fitted. Details of the stay hole 290 and the bush 40 will be described later.

  The stator 4 is arranged to face the outer periphery of the rotor 10 and includes a stator core 5 and a stator winding 6. The rotor 10 includes a field winding 11, pole cores 12 and 13, a rotating shaft 14, etc., and is rotatably held by a pair of bearings 15 and 16 fixed to the bearing boxes 7 and 8. And rotate together. Centrifugal cooling fans 17 and 18 are attached to the axial end surfaces of the pole cores 12 and 13. The cooling fan 17 on the front side is a mixed flow type in which the blades are inclined forward with respect to the rotation direction of the rotor 10 in order to generate cooling air to the field winding 11. A pulley 19 is coupled to the front end of the rotating shaft 14 by a nut 20 and is driven to rotate by a vehicle engine (not shown). Furthermore, a pair of slip rings 21 and 22 are provided at the rear end of the rotating shaft 14 located outside the rear side frame 2, and are electrically connected to the field winding 11 via a conductor 23. Yes.

  So-called electrical components such as the rectifying device 24, the voltage control device 25, and the brush device 26 are fixed to the outer axial end surface of the rear frame 2 by fixing means such as bolts 9 and the like. The rectifier 24 rectifies and converts a three-phase AC voltage, which is an output voltage of the three-phase stator winding 6, into a DC output voltage, for example. The voltage control device 25 controls the output voltage of the vehicle AC generator 100 by adjusting the excitation current flowing through the field winding 11. The brush device 26 is for flowing an exciting current from the rectifying device 24 to the field winding 11 of the rotor 10, and presses each of the slip rings 21 and 22 formed on the rotating shaft 14 of the rotor 10. Has a brush.

  Next, details of the stay hole 290 and the bush 40 of the rear frame 2 will be described. FIG. 2 is a diagram showing the bush 40 press-fitted into the stay hole 290 of the rear side frame 2 and the surrounding structure. A female screw groove 42 is formed on the inner peripheral surface of the bush 40, and a hexagonal portion 44 is formed in the vicinity of the rear side end surface. The stay portion 29 is formed with a convex portion 292 at a position corresponding to one side of the hexagonal portion 44, and the convex portion 292 functions as a detent for preventing the rotation of the hexagonal portion 44.

  In the stay hole 290 of the stay portion 29, a plurality of (many) convex portions 294 are formed on the inner diameter side facing the outer peripheral surface of the bush 40, that is, on the inner peripheral surface of the stay hole 290. FIG. 3 is a view showing the shape of the stay hole 290. FIG. 4 is a diagram showing a detailed shape of the convex portion 294 formed on the inner diameter side of the stay hole 290. The plurality of convex portions 294 are formed in a direction parallel to the central axis of the stay hole 290, that is, in a direction along the insertion direction when the bush 40 is inserted into the stay hole 290. The inner diameters of the tips (tops) of these convex portions 294 are set to be smaller than the outer diameter of the outer peripheral surface of the bush 40, and the bush 40 is press-fitted so as to fit with the stay hole 290 with a tightening margin. . When the bush 40 is press-fitted into the stay hole 290, the vicinity of the tip (top) of the convex portion 294 is elastically deformed, and further plastically deforms as the deformation proceeds. For this reason, even if there is a slight error in the outer diameter of the bush 40 and the inner diameter of the tip of the convex portion 294, the variation in the tightening margin is kept within a predetermined range due to this plastic deformation, and the slide of the bush 40 The load is stable. This tendency becomes more prominent as the number of convex portions 294 is increased. A cylindrical portion that is press-fitted into a stay hole 290 as an attachment hole is provided in a portion of the bush 40 excluding the head portion provided at one end exposed to the outside. The cylindrical portion of the bush 40 has no seam such as a slit extending in the axial direction, and has a strength that does not deform the diameter in a series of press-fitting processes. The cylindrical portion of the bush 40 is directly press-fitted into the stay hole 290 without interposing other members. A plurality of convex portions 294 are provided on the inner wall surface of the stay hole 290 so as to be spaced apart from each other in at least one of the circumferential direction and the axial direction and project inward in the radial direction. A columnar space is defined by the radially inner apexes of the plurality of convex portions 294. The outer diameter of the outer cylindrical surface of the cylindrical portion of the bush 40 is set larger than the diameter of this columnar space. As a result, between the bush 40 and the stay hole 290, it is obtained mainly by deformation of the convex portion 294 for holding and fixing the bush 40 in the stay hole 290 in a state where the bush 40 is press-fitted into the stay hole 290. A predetermined amount of tightening allowance is set.

  As shown in FIG. 4, a concave portion 296 is formed between the plurality of convex portions 294, and the adjacent two convex portions 294 are smoothly connected via the concave portion 296. Thereby, when the bush 40 is inserted into the stay hole 290 of the stay portion 29, excessive stress generated in a part of the concave portion 296 between the adjacent convex portions 294 can be relieved, and damage to the stay hole 290 is prevented. Can be prevented.

  The operation of attaching the vehicle alternator 100 to the vehicle bracket 300 as an attachment portion provided in the engine is performed by passing a bolt (not shown) from the front side of the front frame 1 through the attachment hole 280 of the stay portion 28. After the bolt is passed through the through hole formed in the vehicle bracket 300, the bolt is fastened and fixed by the female screw groove 42 of the bush 40, and the vehicle bracket 300 is sandwiched and fixed by the two stay portions 28 and 29. Is called. When the bolt is tightened in the female screw groove 42 of the bush 40, the bush 40 slides in this direction because a tensile force acts in the direction along the central axis of the bush 40.

  As described above, in the vehicle alternator 100 of the present embodiment, the outer peripheral surface of the bush 40 is partially applied to the tip (top) of the convex portion 294 rather than the entire inner peripheral surface of the stay hole 290 of the stay portion 29. If the tightening allowance between the bush 40 and the stay hole 290 is too tight, excessive stress concentrated on the convex portion 294 is relieved by the deformation of the periphery of the convex portion 294, so that the bush 40 and the stay hole 290 are relaxed. It is possible to prevent the slide load from becoming excessively large due to the dimensional accuracy, and a stable slide load can be obtained. Further, even when the dimensional accuracy of the outer diameter of the bush 40 without splitting and the inner diameter of the stay hole 290 is relatively low, the bush 40 and the convex portion 294 are provided with an appropriate tightening allowance to stabilize. Since a slide load can be obtained, the bush 40 and the stay hole 290 can be manufactured under low dimensional control, and the manufacturing becomes easy.

  Further, by attaching the vehicle alternator 100 having such a structure around the bush to the engine, it is possible to prevent an excessive torsional load from being applied to the rear frame 2 from the stay portion 29 at the time of attachment. The vehicle alternator 100 can be properly and reliably attached to the engine. In particular, even when the tightening force generated by screw tightening using bolts is set to be large when mounted on the engine, the bush 40 slides and the torsional load applied to the rear side frame 2 from the stay portion 29 is made constant. Can do. For this reason, the tightening force generated by screw tightening can be set large, and the stay portions 28 and 29 can be reliably attached to the vehicle bracket 300.

  Further, a female screw groove is formed on the inner peripheral surface of the bush 40, and the screw bracket 40 is fixed to the vehicle bracket 300. The screw bush 40 which is not split can be used, and such a screw can be used. Using the bush 40 eliminates the need for a nut combined with a bolt, thus facilitating work and reducing the number of parts.

  Further, by forming a plurality of convex portions 294 on the inner diameter side of the stay hole 290, the bush 40 can be supported by a large number of convex portions 294, and stress applied to each convex portion 294 can be dispersed. The mounting state of the bush 40 with respect to the hole 290 can be stabilized.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, as in the cross-sectional shape of the stay hole 290 shown in FIG. 5, the convex portion 294 may be formed inside the both end surfaces of the stay hole 290. The convex portion 294 may be formed only in the central portion of the stay hole 290. The axial length of the formation range of the convex portion 294 is set shorter than the axial length of the stay hole 290. As a result, in the stay hole 290, a large-diameter portion that is larger than the diameter of the cylindrical space defined by the top of the convex portion 294 and larger than the outer diameter of the cylindrical portion of the bush 40 is provided. The large-diameter portion can be provided only over a predetermined axial length from at least the stay hole 290 on the end surface on the inlet side where the bush 40 is press-fitted, that is, the rear-side end surface. The large-diameter portion can be provided over a predetermined axial length from the end surface of the stay hole 290 on the opposite side of the bush 40, that is, the front-side end surface. As a result, the convex portion 294 extends toward the back of the stay hole 290, that is, toward the front side with respect to the axial direction, starting from a position at least a predetermined axial length in the stay hole 290. Can be provided. As a result, a portion having a large inner diameter in the vicinity of both end faces of the stay hole 290 can be used as an insertion guide for the bush 40, so that the work for inserting the bush 40 into the mounting hole is facilitated. A slope defining a tapered surface that gradually narrows the inner diameter from the large-diameter portion toward the top of the convex portion 294 may be formed at the axial end of the convex portion 294.

  Further, like the cross-sectional shape of the stay hole 290 shown in FIG. 6, the convex portion 294 may be formed in a spiral shape that continuously circulates on the surface of the stay hole 290 facing the bush 40. As a whole, there is one convex portion 294, but since a plurality of convex portions 294 are arranged when attention is paid to the press-fitting direction of the bush 40, a large number of convex portions are provided in the same manner as the plurality of convex portions 294 shown in FIG. By supporting the bush 40 by 294, there is an effect of dispersing the stress applied to each convex portion 294. Thereby, the stable slide load of the bush 40 is realizable.

  In the above-described embodiment, the AC generator 100 for a vehicle is described as an embodiment of the rotating electrical machine. However, the present invention can also be applied to a case where a bush is attached to another rotating electrical machine, for example, a stay portion of an electric motor. it can.

It is a figure showing the whole composition of the alternator for vehicles of one embodiment. It is a figure which shows the bush press-fit in the stay hole of the rear side frame, and its surrounding structure. It is a figure which shows the shape of a stay hole. It is a figure which shows the detailed shape of the convex part formed in the internal diameter side of a stay hole. It is a figure which shows the modification of the convex part formed in the stay hole. It is a figure which shows the other modification of the convex part formed in the stay hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side frame 2 Rear side frame 4 Stator 5 Stator iron core 6 Stator winding 10 Rotor 11 Field winding 24 Rectifier 25 Voltage control device 26 Brush device 27 Rear cover 29 Stay part 40 Bush 42 Female screw groove 44 6 Corner part 100 AC generator for vehicle 290 Stay hole 292 Convex part 294 Convex part 296 Concave part

Claims (8)

A rotor that rotates integrally with the rotating shaft; a stator that is disposed opposite to the outer periphery of the rotor; a frame that houses the rotor and the stator; and a stay that protrudes to the outer peripheral side of the frame. A rotating electrical machine including a portion and a bush that is inserted into a mounting hole provided in the stay portion and slides along a central axis of the mounting hole.
The rotating electric machine is characterized in that a convex portion is formed on the inner diameter side of the mounting hole facing the outer peripheral surface of the bush, and a tightening margin is set between the bush and the mounting hole. In claim 1,
A pulley for transmitting a rotational driving force is attached to the rotating shaft,
The rotating electrical machine, wherein the stay portion and the frame are attached to the engine via the bush, and the pulley is rotationally driven by the engine. In claim 1 or 2,
The frame is constituted by a front side frame including a stay portion having an attachment hole into which the bush is not inserted, and a rear side frame including the stay portion having the attachment hole into which the bush is inserted,
The stay portion provided on the front side frame and the stay portion provided on the rear side frame are screwed and fixed in a state in which an attachment portion on the engine side is sandwiched via the bush. Rotating electric machine. In claim 3,
A female screw groove is formed on the inner peripheral surface of the bush,
The rotating electrical machine is characterized in that the screw tightening and fixing to the mounting portion of the engine is performed using a bolt corresponding to the female screw groove. In any one of Claims 1-4,
A plurality of the convex portions are formed on a surface of the mounting hole facing the bush, and smoothly connect between the adjacent convex portions. In any one of Claims 1-5,
A plurality of the convex portions are formed on the surface of the mounting hole facing the bushing in a direction parallel to the central axis of the mounting hole. In any one of Claims 1-5,
The rotating electric machine is characterized in that the convex portion is formed in a spiral shape that continuously circulates on a surface of the mounting hole facing the bush. In any one of Claims 1-7,
The rotating electrical machine according to claim 1, wherein the convex portion is formed on an inner side than both end faces of the mounting hole.

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